Fan switch

Hi, I'm in the process of changing my radiator and pipe work due to old age, could someone help me with part numbers for the thermostat and also the fan switch (in rad) I'm trying to order but without the numbers can't guarantee it's correct. It's for a 1991 clipper 1.8 carb Cheers.

3 pin indicates that it is a 2 speed fan that you have on your car.

Usually you see that on a/c equipped models.

3 pin 191959481C
2 pin 191959481b

Book mark:

https://volkswagen.7zap.com/en/rdw/

Finding things is funny as the radiator stuff is in the engine section, whereas the radiator fan switch are in the electric.   

Cooling refers to the a/c circuits.  

Why change the old senor from your old radiator unless it’s faulty?
When I changed my radiator I just unscrewed it and fitted it to my new radiator with a little blue hylomar to help seal it.

https://www.ebay.co.uk/itm/Hylomar-Blue-Instant-Gasket-Non-Setting-Jointing-Compound-Sealant-Maker-40g/142791008164?epid=693720071&hash=item213f01dfa4:g:SXsAAOSwozxa9aGV

I would test it first myself but if I was fitting a new radiator I would fit a new switch after testing the new one as well.

Thank you all for you help and advice. The parts site is ace and found what I needed. Thanks again.